OOP begginer organising project

Ok, I started a few days ago to learn OOP. Basic concepts I understand but now I want to create a project and use Design Patterns in it, so the first idea was with singleton patterns.I have 3 tiers GUI-BL-DAL on GUI I have MVC but that is not important now. I want to find the best way to communicate between this tiers so the first idea was:BL classes: Manager, BookManager, MemberManager, EmployeeManager;DAL classes: Storage, BookDAL, MemberDAL, EmployeeDAL;